1. Field of the Invention
The present invention relates to an object encoding method for an arbitrary shape, and more particularly, to a method of effectively coding an arbitrary shape of an object when all pixels of the entire region of a display are used as a texture of an object.
2. Description of the Related Art
As shown in FIG. 1, an object having an arbitrary shape is generally classified as having a shape and a texture.
A conventional arbitrary shape coding method, e.g., described in the MPEG-4 Video VM (Version 7.0), is performed by the steps shown in FIG. 2.
First, it is determined whether or not the shape in a video object layer (VOL) is an arbitrary shape (step 110).
If the shape in the VOL is an arbitrary shape, the size of the object (width, height, etc.) is calculated for each frame which is a video object plane (VOP) (step 120), and then coding of motion, shape and texture of each block is performed (step 140).
On the other hand, if the shape in the VOL is not an arbitrary shape, a rectangular frame is previously determined, so that coding of only motion and texture is performed by macroblock (step 150).
As shown in a time frame t+3 of FIG. 3, all pixels of the entire region of a screen may be used as the texture of an object having an arbitrary shape, in certain screens. When performing shape coding using the conventional method shown in FIG. 2, shape information on each macroblock constituting the screen must be included in a transmission data stream, even when the entire screen is occupied by only the texture of the object having an arbitrary shape.
When the texture of the object occupies the entire of screen, the shape information by macroblock is useless. Thus, it is ineffective to include such useless information in the transmission data, because the shape information requires extra time for computation.